Indazolone colour couplers



United States Patent C F INDAZOLONE COLOUR COUPLERS John Mathers Woolley, Blackley, Manchester, England, assignor to Imperial Chemical Industries Limited, a corporation of. Great Britain Application December 7, 1953 Serial No. 396,730

Claims priority, application Great Britain December 10, 1952 No Drawing.

8 Claims.

or a tautomeric form thereof, wherein Z represents the non-metallic atoms required to complete an isocyclic, heterocyclic or polycyclic nucleus. The colour image obtained in this way is formed by the coupling of the oxidation. product of the developer on the 2 position of the indazolone ring, that is to say on the N-atom which is in the ortho-position to the carbonyl group.

With certain 2-substituted indazolones, the colour coupling takes place in an entirely different way, the indazolone ring is broken andv an azo compound is formed .in which the residue of the oxidation product of the developing agent is attached to the nitrogen atom which previously formed the l-nitrogen atom of the indazolone ring.

We have found that when the substituent on the 2-position of the indazolone ring is a carbalkoxy group and there is a sulphonamide group as substituent in the S-position, valuable magenta colour formers are obtained.

According to our invention therefore, we provide new colour couplers of the formula:

wherein R and R represent hydrogen atoms or hydrocarbon radicals and R represents a hydrocarbon radical, provided that when R is hydrogen and R is l-naphthyl the naphthyl radical must carry a substituent in the 4- position.

The colour couplers of our invention are particularly valuable because owing to the pronounced bathochromic elfect of the sulphonamide group they give magenta azo dyestuffs on colour development with aromatic amino developing agents, for example p-diethylaminoaniline, whereas the parent Z-carbalkoxy-indazolones without the sulphonamide group give orange azo dyestuffs under these conditions. Also when substituents other than carbalkoxy are present in the 2-position, the bathochromic effect of the sulphonamide group is generally accompanied by a marked reduction in reactivity, in which case the 2-substituted indazolones do not react sufficiently readily under the conditions of colour photographic development, or H 2,866,706 l atented Dec. 30, 1958 by an increased ease of hydrolysis, in which case the 2-substituent is hydrolysed off. and coupling to form' an azo dyestuff does not occur. The Z-carbalkoxy-indazolone-S-sulphonamides of our invention however have excellent all round properties, and in particular they have good stability and high coupling activity, and unlike the known indazolone colour couplers containing no substituent in the 2-position, they do not give yellow oxidation products in the bleaching. bath used for removal of silver.

The colour couplers of our invention may be used in. the deevloping solution or they may be included in. a light-sensitive layer or in a nondight-sensitive layer. adjacent to a sensitive layer or separated therefrom by a. water-permeable colloid layer.

It is a preferred feature of. our invention to includethe colour couplers in one or more light-sensitive gelatinosilver halide emulsion layers which form part of a multilayer film or paper of the kind used. for colour photog raphy. For this purpose it is preferred to use colour couplers which contain. a substituent rendering them fast to diffusion, for example a long alkyl chain containing at least 5 carbon atoms and if desired a solubilising group. Other substitutents may be present especially in the 4, 6 and 7 positions of the indazolone ring.

Specific examples of the colour formers of our invention are Z-carbethoxy-S-(N-p-dodecyl-phenyl-sulphamyl)?- indazolone, Z-carb-octadecoxy-S-N-phenylsulphamyl-ine dazolone, 2-carb-octadecoxy-S-N-phenyl-N-methyl-sulphamyl-indazolone and the corresponding sulphonic acid and its salts, Z-carb-octadecoxy-S-(N-3 5"-dicarboxyphenyl-sulphamyl) indazolone, 2 carb octadecoxy-S- (N-4'-sulpho-1'-naphthyl-sulphamyl)-indazolone, 2-carboleyloXy-S-(N-phenyl-sulphamyl)-indazolone and Z-carbiso-amyloxy-S-(N-phenyl-sulphamyl)-indazolone.

The colour couplers of our inventionmay be made. by chlorosulphonating the parent indazolone and reacting the sulphonyl chloride with ammonia or with the appropriate primary or secondary amine, and then treating. the ind:zolone-S-sulphonamide with the appropriate ester: of chloroformic acid to introduce the carbalkoxy group into the 2-position of the indazolone ring..

According to a further feature of our invention we provide a process for producing colour photographic images which comprises developing an exposed gelatino-silver halide emulsion layer with a primary aromatic amino developing agent in the presence of a colour coupler of the formula shown above.

The developing agents preferably used and giving the best results in connection with the present invention are the aromatic orthoand para-diamines such as paraphenylene diamine and its substitution products.

The colour coupling which occurs in the process of our invention when. an exposed gelatino-silver halide emulsion is treated with a primary aromatic amino developing agent in the presence of a colour coupler of the kind used in our invention proceeds by a surprising and wholly unexpected reaction, in which the indazolone ring is split and an azo dyestufr' is formed in which the residue of the oxidation product of the developing agent is attached to the nitrogen atom which previously formed the l-nitrogen atom of the indazolone ring. For example when 2-carbethoxy-S-(N-p-dodecylphenyl sulphamyl)-ind-azolone is used as the colour coupler and p-diethylaminoaniline is used as the developing agent a dyestulf is formed which is believed to have the following formula:

Ciiz nGNH-S O It will be noted that the substituent. Gut-he nitrogen atom;

' 3 in Z-position of the indazolone ring is not split off during colour development.

According to a further feature of our invention therefore we provide a colour photographic element which contains in at least one emulsion layer a colour image comprising a dyestufi of the formula:

N-SOr CO-NH-COORa wherein R R, and R have the significance given 'above and X represents the group of atoms which together with the group -NH, forms a primary aromatic amino developing agent.

The dyestufi images formed by the process of our invention are superior to the known azomethine images in their chemical stability and their fastness to light and the process of our invention provides a simple method of obtaining colour photographic images of good fastness properties by direct development of an exposed gelatinosilver halide emulsion with aromatic amino colour developers.

The invention is illustrated but not limited by the following examples in which the parts are by weight:

Example 1 10 parts of indazolone are added to 50 parts of chlorosulphonic acid which is well stirred at 40 C. The solution is stirred at 40 C. for 6 hours and then poured into 200 parts of ice.

The mixture is well stirred and the indaz olone-- sulphonyl-chloride which is precipitated, is filtered off, washed acid free with ice cold water and dried in a vacuum desiccator. The dry indazolone sulphonyl chloride is added to a solution of 50 parts of p-dodecylaniline in 150 parts of dioxane and the mixture is heated until a clear solution is obtained. The solution is poured into water and the suspension so obtained is made alkaline by the addition of caustic sod-a and extracted with ethyl acetate. The residual aqueous solution is acidified with acetic acid and the S-(N-pdodecylphenyl-sulphamyl)-indazolone so precipitated is filtered off, dried and purified by recrystallisation from methanol,

10 parts of the purified compound are heated under a reflux condenser with 60 parts of dioxane and 5 parts of ethyl chloroformate until the evolution of hydrogen chloride has ceased. The reaction mixture is cooled and the Z-carbethoxy 5 (N-p-dodecylp'henyl sulphamyl)-indazolone (melting point 203 C.) which crystallises out, is filtered off and washed with methanol and then with ether and dried.

The product can be added to a photographic developer solution or it can be incorporated into light sensitive gelatincysilver halide emulsions which are used for forming sensitive photographic layers and on exposure and colour development, it gives a magenta dyestufi image which has much better stability to light and acid fumes than the azomethine dyestuff images formed by colour development from conventional colour formers.

Example 2 10 parts of indazolone-S-sulphonyl chloride are heated the mixture is boiled under a reflux condenser until the evolution of hydrogen chloride has ceased. The mixture is cooled and 2-carb-octadecoxy-5-(N-phenyl'sulphamyly indazolone (melting point 180 C.) which crystallises out is filtered otf, washed with methanol and then with ether and dried.

Example 3 In place of the 7 parts of aniline used in Example 2, 9.0 parts of methylaniline are used when Z-carb-octadecoxy 5 (N-phenyl-N'-methyl-sulphamyl)-indazolone (melting point 150 C.) is obtained.

10 parts of the product are added to 200 parts of dry ethylene dichloride. The mixture is stirred and 10 parts of chlorosulphonic acid are added. The mixture is stirred and heated at 60 C. for 30 minutes and then poured into 300 parts of water. The mixture is made alkaline by the addition of caustic soda and then allowed to stand for 1 hour. The lower layer of ethylene dichloride is run off, and the upper (aqueous) layer is filtered through kieselguhr. The filtrate is acidified with hydrochloric acid and 20 parts of common salt are added. The mixture is stirred and the precipitate is then filtered off, and boiled with 50 parts of methanol. The mixture is cooled and filtered and the residue washed with ether and dried. The sulp'honated product so obtained melts at 256 C. and is readily soluble in dilute sodium carbonate solution.

An aqueous solution of the product can be added to a gelatino-silver halide emulsion prior to coating on a film.

The product gives a magenta image on exposure and colour development.

Example 4 12 parts of indazolone-S-sulphonyl chloride are stirred with 15 parts of the diethyl ester of aniline-3:5-dicarboxylic acid in 70 parts of dioxanc until a clear solution is obtained. The solution is poured into an equal volume of water and then acidified with hydrochloric acid and the precipitate is filtered off. The precipitate is stirred with 250 parts of water and caustic soda solution is added until the solution is alkaline to phenolphthalein. The solution is boiled for 30 minutes to hydrolyse the ester, further additions of caustic soda being made to keep the solution alkaline to phenolphthalein. The solution is then treated with decolourising carbon and filtered. The filtrate is acidified to Congo red paper with hydrochloric acid and the 5-(N-3':5-dicarboxyphenyl-sulphamyl)- indazolone which is precipitated is filtered off, washed and dried.

A mixture of 10 parts of 5-(N-3':5-dicarboxyphenylsulphamyl)-indazolone, 30 parts of the chlorobenzene solution of octadecyl chloroformate made as described in Example 2 and 100 parts of dry dioxane are boiled under a reflux condenser for 6 hours. 300 parts of methanol are added and the mixture so obtained is cooled. The white precipitate so formed is filtered ofi, washed with methanol and then with ether and dried. 2-carbocta decoxy-5-(N-3':5'-dicarboxyphenyl-sulphamyl) indazolone is obtained as a white powder (melting point 244 c.)

The product dissolves readily in aqueous sodium car bonate to give a clear yellow solution, which may be incorporated in a gelatino-silver halide emulsion, to form an emulsion suitable for the preparation of the magenta layer of a multi-layer colour photographic ma terial.

Example 5 12 parts of indazolone-S-sulphonylchloride are added to 30 parts of a-naphthylamine in parts of acetone and the mixture is warmed on a water bath until a clear solution is obtained. This solution is diluted with an equal volume of water, acidified with hydrochloric acid and cooled and the S-(N-a-naphthyl-sulphamyl)-indazolone (melting point 250 C. with decomposition) which is precipitated, is filtered off, washed with dilute hydrochloric acid and dried. A mixture of 10 parts of this product 30 parts of the chlorobenzene solution of octadecyl chloroformate prepared as described in Example 2, and 100 parts of dioxane are heated under a reflux condenser for 3 hours. 300 parts of methanol are added, the mixture so obtained is cooled and the precipitate of Z-carb-octadecoxy-S-(N on naphthyl sulphamyl)-indazolone is filtered E and dried when it is obtained as a white powder of melting point 164-166 C. 10 parts of this product are stirred with 50 parts of dry ethylene dichloride and 8 parts of chloro-sulphonic acid are added at a temperature not higher than 30 C. The mixture is stirred for 1 hour and the solid in suspension is then filtered oif, washed with ethylene dichloride, and dried. The Z-carb-octadecoxy 5 (N 4' sulpho 1' naphthyl-sulphamyl)-indazolone so obtained as a white solid melting with decomposition at 245-250 C. dis

solves in aqueous sodium carbonate and the solution so obtained may be added to a gelatino-silver halide emulsion to give an emulsion suitable for forming the magenta image layer of a colour photographic material.

Example 6 60 parts of a solution contatining 1 gram mol. of oleyl chloroforrnate in 1 litre of chlorobenzene (prepared by reacting oleyl alcohol in chlorobenzene solution with phosgene) are added to a mixture of 6 parts of 5-N- phenylsulphamyl-indazolo-ne and 50 parts of dioxane and the mixture is boiled under a reflux condenser until the evolution of hydrogen chloride has ceased. I

The solvent is then removed by distillation under reduced pressure and 400 parts of methanol are added to the residue. The precipitate is filtered ofi, washed with methanol and dried. The Z-carb-oleyloxy-S-(N-phenylsulphamyl)-indazolone so obtained dissolves readily in oils, for example medicinal paraffin, to form solutions suitable for suspension in gelatino-silver halide emulsions to form emulsions which give magenta images on exposure and colour development.

Example 7 wherein R is a member of the group consisting of hydrogen and alkyl, R is a member of the group consisting of an aryl radical of the benzene series, an aryl radical of the naphthalene series and carboxy and sulfonic acid substituted aryl radicals of said benzene and naphthalene series with the further proviso that, when R is hydrogen and R is l-naphthyl, the naphthyl radical carries a substituent in the 4-position, and R is a member of the group consisting of an alkyl and an alkenyl group.

2. Process for producing colour photographic images which comprises developing an exposed gelatino-silver halide emulsion layer with a primary aromatic amino developing agent in the presence of a colour coupler of the formula R1 00 N-SO 5 4 3 R2 2N-COOR:

Where R is a member of the group consisting of hydrogen and alkyl, R is a member of the group consisting of an aryl radical of the benzene series, an aryl radical of the naphthalene series and carboxy and sulfonic acid substituted aryl radicals of said benzene and naphthalene series with the further proviso that, when R is hydrogen and R is l-naphthyl, the naphthyl radical carries a substituent in the 4-position, and R is a member of the group consisting of an .alkyl and an alkenyl group.

3. A gelatino silver halide emulsion as defined in claim 1 wherein said colour coupler is 2-carb-ethoxy-5-(N-pdodecylphenylsulphamyl)-indazolone.

4. A gelatino silver halide emulsion as defined in claim 1 wherein said colour coupler is 2-carb-octadecoxy-5- (N-phenyl-N'-methyl-sulphamyl)-indazolone.

5. A gelatino silver halide emulsion as defined in claim 1 wherein said colour coupler is 2-carb-octadecoxy-S- N-3 5 '-dicarboxyphenyl-sulphamyl -indazolone.

6. A gelatino silver halide emulsion as defined in claim 1 wherein said colour coupler is 2-carb-octadecoxy-5- (N-4-sulpho-1-naphthyl-sulphamyl)-indazolone.

7. A gelatino silver halide emulsion as defined in claim 1 wherein said colour coupler is Z-carb-oleyloxy-S-(N- phenyl-sulphamy)-indazolone.

8. A photographic developer solution containing a primary aromatic amino developing agent and a colour coupler of the formula:

References Cited in the file of this patent- UNITED STATES PATENTS 2,428,108 McQueen Sept. 30, 1947 2,499,265 Bouvier Feb. 28, 1950 2,511,231 Weissberger et al. June 13, 1950 2,625,329 McCrossen et a1 Sept. 15, 1953 2,673,801 Jennen Mar. 30, 1954 OTHER REFERENCES Gadamer et al.: Chem. Abstracts, vol. 15, p. 3273 (1921).

Pieroni et al.: Chem. Abstracts, vol. 18, p. 3177 (1924). 

1. A GELATINO SILVER HALIDE EMULSION CONTAINING A COLOUR COUPLER OF THE FORMULA: 